Elevated Rest on Herter's Sitka

[Sarge5706]

I just bought a Herter's Perfection Sitka bow.  It came with an elevated rest which I have replaced with a rug rest as I like shooting off the shelf.  I have sent about 50 arrows down range and seem to have trouble hitting at 20 yards.  With most shoots going low or to the right.
Am I hitting low because I am unfamiliar with the bow or should I put an elevated rest on and see if that helps.
I should add that I get solid hits with my other bows at the same distance, same pull weight, same arrows.

[mahantango]

Sounds like you just need to play around with the tuning. Nock point, strike plate thickness, arrow spine etc. Remember, not all bows of the same draw weight shoot the same spine, amount of center shot makes a lot of difference. Also,, some of those old Herters had a weird shelf cut and were meant to use a elected rest. Can you post a picture of the riser?

[Sarge5706]

Thanks for the input and apologize for the delay in getting back to you.  Don't have a picture at current time that shows the riser but will say that it came with an elevated rest and the riser curves into the self.  I have done some tuning with the nock and am getting decent groups but will start to hit low. I am going to try experimenting with the arrows this weekend.
I know one thing is that this bows physical weight is much heavier than anything else I have been shooting and I find that towards the end of the session I start shooting lower.